1. Field of the Invention
Embodiments according to the invention relates to network interface cards. More particularly, embodiments according to the invention relate to providing a single network interface card that is user selectable to work with two different networking protocols.
2. Description of the Related Art
Effectively deploying multiple devices in a network environment becomes an increasingly complex task as transmission data rates, processor speeds, and storage capacities increase. Storage area networks (SANs) have been developed as specialized high-speed networks, referred to as fabrics, to connect computer systems, control software, and storage devices over the fabric. SANs typically allow block level input/output (I/O) rather than file-level access. Thus, every device connected to a SAN fabric appears as a locally attached device to other devices on the fabric.
Local area networks (LANs) are used to connect devices, but primarily for file level transfers. LANs are used to connect servers together in data centers as well as connecting individual workstations to servers. Therefore it is very common for large data centers to have two networks, a LAN for communication with workstations and a SAN for storage.
FIG. 1 shows components in a prior art blade chassis 101. The blade chassis 101 includes a Fibre Channel switch 102, an Ethernet switch 103 and a series of host blades 104. Each host blade 104 has a processor 106, a bridge 108, memory 109, an Ethernet network interface 107 and a host bus adapter (HBA) 110. Conventionally, the HBA 110 is a daughter or mezzanine board connected to the host blade 104. Also conventionally one Ethernet interface 107 is present on the host blade 104 itself but an additional Ethernet interface 107 can be present as a daughter or mezzanine board as well. Each memory 109, connected to the bridge 108, contains queues that comprise command and completion rings for data sent to and received from the Ethernet interface 107 and the HBA 110. The bridge 108 handles I/O processes and provides an interface between devices internal to and external to the host blade 104 (e.g., central processing unit (CPU) 106, HBA 110). As an example, the bridge 108 can provide PCI-Express (PCI-E) connections to the HBA 110 and the Ethernet interface 107. Each HBA 110 connects the respective host blade 104 to other network and storage devices 114 on an enterprise fabric 112 via the Fibre Channel switch 102. As is known in the art, each HBA 110 has a unique World Wide Name (WWN), which identifies the HBA 110, and thus the respective host blade 104, to the Fibre Channel switch 102 and other devices on the enterprise fabric 112. Similarly, each Ethernet interface 107 has a unique MAC address for a similar purpose.
One approach being developed to address the dual fabric environment of the data center is a converged Ethernet network. A converged, enhanced Ethernet (CEE) network will use converged network adapters (CNAs). A CNA is capable of operating according to 10G Ethernet but also using a new protocol being developed referred to as FCoE or Fibre Channel over Ethernet. In a simple explanation, FCoE uses the FCP packets and commands normally used in Fibre Channel but places them in Ethernet packets rather than FC packets. Currently FCoE to FC bridges are available to allow a CEE network and servers or hosts with CNAs to access existing FC SANs. Eventually it is believed that storage devices will eventually be converted to FCoE and attach directly to the CEE network. But it is also understood that FC SANs will remain in use and continue to be installed for some period of time.
This developing situation of CEE networks and FC SANs presents problems for both manufacturers and users. For a native connection to the FC SAN, an FC HBA is needed. For connection to the CEE network, a CNA is needed. Therefore both the manufacturer and the user have to inventory and install two different cards or boards, an FC HBA and a CNA. This multiple inventory situation requires more devices and SKUs and also can lead to confusion and misconfiguration. Further, if a user desires to convert from an FC HBA to a CNA, as in a blade server chassis, the user must not only replace the switch in the chassis but also must remove each blade and change the mezzanine board. In a conventional server, to convert would require opening up the server to exchange an FC HBA and a CNA in the unit. Both of these operations greatly increase the time and trouble required to convert from directly connecting to an FC SAN to connecting to a CEE network for storage applications. It would be desirable to reduce the need to inventory two different cards or boards and also to allow users to reconfigure a server or blade without having to remove components inside a server or on a blade.